<script setup>
import { ref, watch } from "vue";
import { useMouseInElement } from "@vueuse/core";

// props接收图片列表
defineProps({
  imageList: {
    type: Array,
    default: () => [],
  },
});

// 1.小图切换大图显示
const activeIndex = ref(0);

const enterHandler = (i) => {
  activeIndex.value = i;
};

// 2. 获取鼠标相对位置
const target = ref(null);
const { elementX, elementY, isOutside } = useMouseInElement(target);
const left = ref(0);
const top = ref(0);
watch([elementX, elementY], ([newX, newY]) => {
  // 如果不在目标区域内，则后续不处理
  if (isOutside.value) return;
  if (newX > 0 && newX < 100) left.value = 0;
  else if (newX > 100 && newX < 300) left.value = newX - 100;
  else if (newX > 300 && newX < 400) left.value = 200;
  if (newY > 0 && newY < 100) top.value = 0;
  else if (newY > 100 && newY < 300) top.value = newY - 100;
  else if (newY > 300 && newY < 400) top.value = 200;
  backgroundPositionX.value = `-${left.value * 2}px`;
  backgroundPositionY.value = `-${top.value * 2}px`;
});

// 3.右侧大图显示
const backgroundPositionX = ref(0);
const backgroundPositionY = ref(0);
</script>

<template>
  {{ elementX }},{{ elementY }},{{ isOutside }}
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle" ref="target">
      <img :src="imageList[activeIndex]" alt="" />
      <!-- 蒙层小滑块 -->
      <div
        class="layer"
        v-show="!isOutside"
        :style="{
          left: `${left}px`,
          top: `${top}px`,
        }"
      ></div>
    </div>
    <!-- 小图列表 -->
    <ul class="small">
      <li
        v-for="(img, i) in imageList"
        :key="i"
        @mouseenter="enterHandler(i)"
        :class="{ active: i === activeIndex }"
      >
        <img :src="img" alt="" />
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div
      class="large"
      :style="[
        {
          backgroundImage: `url(${imageList[activeIndex]})`,
          backgroundPositionX: backgroundPositionX,
          backgroundPositionY: backgroundPositionY,
        },
      ]"
      v-show="!isOutside"
    ></div>
  </div>
</template>

<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  img {
    width: 100%;
    height: 100%;
    object-fit: cover;
  }

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>
